Members of the Mongrel Mob and Black Power gangs had to be separated by police officers and security staff in Whanganui District Court on Wednesday.
Tempers exploded as a defendant had a charge of murdering Mongrel Mob member Kevin Neihana Ratana put to him and pleaded not guilty.
After making his plea, the defendant, who has interim name suppression, began yelling obscenities causing chaos as supporters of Ratana retaliated.
Police and security presence was already high in the courtroom that was full of tension with members of both gangs represented inside.
Half of them removed the defendants from the courtroom, while the other half removed Ratana's supporters from the court.
As police and security made their way back up from the cells where they had returned the defendants, several could be seen receiving messages and then sprinting outside.
It is believed that there was an altercation outside of Whanganui District Court and arrests have been made.
Senior Sergeant Shayne Wainhouse said he had no comment to make at this time.
Meanwhile in the court proceedings, seven men appeared charged with murdering 27-year-old father-of-two Kevin Ratana.
They appeared in Whanganui District Court for a call-over hosted via audio visual link where two of them pleaded not guilty and the rest are yet to enter a plea.
The Judge ordered that the defendants retain interim name suppression for at least another week allowing time for further applications to be made.
The defendants will appear in the court again for a case review hearing on February 7, 2019 at 9am.
Ratana was shot outside his Puriri St home in Whanganui on August 21 as he left to go to the gym.
Known as Kastro, Ratana was an aspiring rapper and patched member of the Mongrel Mob gang. His tangi was held on the River Road in Parikino on August 27.
It attracted an increased police presence, including eye-in-the-sky Eagle helicopter as gang numbers in Whanganui swelled to over 100.
Ratana left behind two sons and a partner.